Shovel-handle lathe



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J. S. BUTTERFIELD' 8v J. B. BRYANT.

sHovEL HANDLE LATER.

" No. 247,743.. c Patented om.. 4,1881.

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J. BTTERFIELD &` J. B. BRYANT. sHoVBL HANDLE LATHB.

410.2473414. Patented' oct. 4,1881; 4

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UNrTnn STATES PATENT @raices JEREMIAH S. BUTTERFIELD, OF VASSALBOROUGH, AND' JAMES B. BRYANT, OF VATEBVILLE, MAINE.

SHOVEL-HANDLE LATHE.

SPECIFICATION forming part of Letters Patent No. 247,743, dated October 4, 1881.

(No model.)

To all whom it may concern Be it known that we,JERnMiAH SBUTTER- FIELD and JAMES B.BRYANT, citizens ot' the United States, residing the rst in Vassalborough and the second at'Waterville,both in the county of Ken nebec and State of Maine, have invented certain new and usefullmprovements in Shovel-Handlel'iathes; and we do hereby declare the following to be a full, clear, and exact Io description oftheinvention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or ii gures of reference in arked thereon which form a part of this specification.

Our invention relates to that class of lathes used for turning shovel-handles; and theobject of our invention is to provide means by which the hardest of wood may be turned zo easily and rapidly.

Elitherto lathes of this kind have been so constructed that many handles were spoiled by the vibration of the parts ofthe machine which held the knife, and the restswhich were intended to hold the handle steadily in place. The knifebar being immovable, the shaving which the knife took from the handle was of a uniform thickness, that thickness being considerable in order to secure rapid work. The consequence 3o was that when the handle came down to its proper size for linishing it was often unable to resist the strain which the knife exerted upon it, and would vibrate to vsuch an extent that its shape would be spoileththerests and the bearers which came against it being unable to hold it in place.

We overcome this clifticulty,t`1rst, by making ourknife-bar swing on trunnionsin such aman- 11er that as the handle is turned theshaving is 4o made thinner and thinner until, when the handle is smallest, the shaving is very thin andthe resistance to the knife correspondingly small; second, by constructing the jaws of our lathe with Web and flanges of solid, or nearly solid,

cast-iron, the wholejaw forming one solid and continuons piece.

In the accompanyingdrawings, Figurelrepresents an end view of our lathe. Fig. 2 represents a section through the line x x, Fig. 3.

5o Fig.3represents a front elevation. Fig. 4 represents a section showing the position of the knifebar and bearings when the handle is just being iinished. Fig. 5 represents a detail of the cam which gives the knife-bar its motion.

A and B are the twojaws of the lathe, each hung to the bed of the lathe by trunnions. Each jaw is composed o t' a solid castingof iron, having a considerable thickness. The jaw B carries the rest b, which is so regulated as to come against the handle as it is being turned 6o down. Thejaw A carries the bearer or resta, the end of which rests on an inclined plaue,so that it rises as the jaw advances. The knifebeam C is pivoted to the top of the jaw A,and projecting back from each end of itare the arms c. Hinged to the ends of these arms are the sweeps or rods c2, the lower ends of which are connected with the eccentrics c7. The axes of 'these eccentrics project from the side of the jaw, and on their ends are cranks c3, over which 7c play the slotted rods c4, one end of which is pivoted to the body of the lathe. The position of the eccentrics and the cranks is such that when the jaw moves up the rods c2 are raised. c5 is the knife, opposite and immediately below the edge of which projects the guard c6. D is the head-center ofthe lathe, on which the handle is placed to be turned.

The jaws are operated by means of levers connected with a` handle, by which they are 8o made to approach each other when a shovelhandle is to be turned; but7 being no part of our invention, and not necessary to illustrate it, we will not describe their action.

The knife here shown is straight and not curved, as in actual shovel-handle lathes, but it serves to illustrate our invention.

Ourinvention operates as follows, viz: When the jaw A tirst begins to move forward the thickness ot' the shaving is considerable, this 9o thickness being governed by the distance between the edge of the knife and the end of the guards c6. The handle is then quite heavy, and is able to bear without springing the strain from the knife. As the jaw continues to move forward the crank c3 comes against the end of the slot in the rod c4, and is thus forced back, turning the eccentric c, which in turn raises the rod c2 and the arm c. As the arm c is raised theknife-beam Gis turned and the knife drawn roo back, diminishing the distance between it and the end of the guard c6, and thus making the shaving' thinner. Finally, when the handle is finished, the shaving` is very thin.

The position of the knife and the parts that support the handle at this pointis seen in Fig. 4.

The eccentric 0"* is arranged in such a position that when the jaw first begins to move np it turns the knife-beam comparatively little; but when the cut is nearlyv completed it inoves faster. In this way We get a thick shavingin cutting' down the rough surface and a thin one in finishing.

The peculiar forni and construction of my jaws co-operate with my movable knife-beam to prevent any motion of the handle while being` turned by holding the various bearings which come againstiLwith great firmness. le are thus able to do good work7 even when our movable knife-beam is not used and a shaving,` of considerable thickness is taken from the handle.

It is evident that there arc a variety of ways in which the knife-beam may be swung as described; but We have shown what We consider 

